Aligning a pair of shafts can be a time consuming task. One of the methods presently used mounts an adjustable dial indicator on one of the shafts and contacting the top of the other shaft. The indicator is set at zero and the shaft with dial indicator rotated and readings taken at 90 degree intervals around the circumference of the stationary shaft. These readings are used to interprete parallel misalignment between the two shafts. Next the stem of the dial indicator is rested on the end of and near the outside diameter of the stationary shaft. The dial is set on zero, the shaft rotated and readings again taken at 90 degree intervals to determine angular displacement. One of the shafts is moved and the process repeated until it checks out properly. When the shafts are experiencing parallel misalignment in two directions and angular misalignment in two directions it is very difficult to visualize the three dimensional position of one shaft with respect to the other in order to make the correct moves. Another known method of aligning two shafts use reverse indicator readings. In this method a dial indicator is placed on one shaft contacting the outer diameter of the other shaft and readings are taken at 90 degree intervals. Next the dial indicator is placed on the other shaft contacting the first shaft and readings are taken. These readings are plotted to determine needed movement to obtain proper alignment. A time consuming method that also requires considerable training.
In U.S. Pat. No. 3,192,631 to Goguen, et al- a pair of telescopes with parallel axial alignment with respect to an end of a long shaft were used to sight on a pair of targets aligned as to the telescopes with the targets movable along the shaft to check on shaft alignment.
It was discovered that a pair of shafts may be directly aligned without the need to rotate either of the shafts.